public class 打印数字的每一位 {
    public static void printNum(int a) {
        if(a<10) {
            System.out.print(a);
        }else {
            printNum(a/10);
            System.out.print(" "+a%10);
        }
    }
    public static void main(String[] args) {
        int a = 1234;
        printNum(a);

    }
}
